Poly prepreg

They are generally used in the form of prepregs 70% fibres/30% matrix of epoxy, poly-imide or phenolic resin. 

In Table 15.3 are shown the chemical structures and Tg and of some representative thermoplastic polymers for use at high temperature (3,9). These matrices have high continuous service temperatures (120-200° C) even under wet environmental conditions. Advantages of thermoplastic over thermoset matrices are their shorter fabrication cycle (generally controlled environment storage is not required) and the possibility to be reprocessed and reconsolidated after manufacture. Poly(ether ether ketone) is a strong contender with epoxy resins for use as a matrix in composite prepregs with carbon fibers to be utilized in structural aircraft components. 

Auxiliary agents binders are needed in prepregging step (poly imide is an example of such binder) ... 

The application of polymer systems with an alternative curing mechanism gives the opportunity to shape concrete and the textile reinforcement in only one step. Furthermore a non-economic way of curing can be avoided and one separate process-step - the curing of the prepreg - can be canceled. ISF and ITA are developing a coated and flexible prepreg reinforcement structure for FRC. Thus, flat and poly-shaped structural FRC parts could be realized. 

High molecular weight soluble polylmides are Indeed "poly-quinoxallne"-llke In their physical properties. Unfortunately the complete elimination of solvent In molding powders and prepreg was not easily achieved In our laboratories and thus, the formation of void free functional articles has proven difficult. Also their requirement for high processing temperatures and somewhat diminished thermophysical profile Is expected to limit commercial acceptance Into engineering end uses. 

The polymers are used as molding resins for optical articles, since the transparency roughly corresponds to that of poly(methyl methacrylate), but the resistance to scratching and abrasion is about 30-40 times better than in PMMA. Poly(diethylene glycol bisallyl carbonate) is used, for example, for the lenses of sunglasses. Since the cured resins have an electrical conductivity which is somewhere between those of porcelain and poly(tetrafluoroethylene), they are used for electrical insulation. Prepolymer-soaked resin mats are obtainable commercially as prepregs. 

Paper roll phenolic resin prepreg /r i/75-l,4-Poly(isoprene), gutta percha (BS)... 

TABLE III. Typical cure sequence for poly[2,2 -(m-phenylene)-5,5 -b1 benzimidazole] prepolymer in a carbon fiber prepreg [13]. 

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